Apparatus for driving wedges in armature slots



W. L. EVANS June 10, 1952 APPARATUS FOR DRIVING WEDGES IN ARMATURE SLOTS Filed May 9, 1946 INVENTOR: Mil/4M A. EMA/ 2 Y: HIS ATTORNEY.

Patented June 10, 1952 APPARATUS FOR DRIVING WEDGES IN ARMATURE SLOTS William L. Evans, Gary, Ind. Application May 9, 1946, Serial No. 668,345

This invention relates to apparatus for driving out wedges and more particularly for driving out retainer wedges which are used to secure armature windings in place. Armature windings are received in slots in the armature body which is made by assembling together a large number of relatively thin circular metal discs. Each disc is provided with circumferentially spaced openings of a shape and size to receive the armature windings, the insulating medium, and the wedge which rests on top thereof. The discs are die-punched so that sharp or 3 Claims. (01. 29-203) slightly burred edges exist around the edges of the slot. Furthermore, there may be slight misalignment of the discs during assembly into the armature body. As a result, the slot formed is generally slightly irregular in contour and presents sharp or burred edges which obstruct the movement of the wedge therethrough. Prior to my invention, great difficulty was encountered in driving the wedges in and out of the slots. This was commonly done by inserting a flat steel bar into the slot and pounding on it with a mallet. The bar often bent and caught on the edges of the discs in the slot. The wedge itself was damaged and even completely destroyed at times.

It is an object of my invention to provide a tool which is simple in construction and positive in action for use in driving wedges into and out of armature slots.

This and other objects will be more apparent after referring to the following specification and attached drawings, in which:

Figure 1 is a side view of the tool;

Figure 2 is a sectional view taken on the line IIII of Figure 1;

Figure 3 is a sectional view taken on the line III-III of Figure 1; and

Figure 4 is an end View of the tool showin it in operating position on a wedge.

Referring more particularly to the drawings the reference numeral 2 indicates the body of the tool which is made from two elongated clamping members 4 and '6 fastened together by means of two bolts 8, each of which passes through a countersunk opening ID in member 4 and an opening 12 in member 6 with the countersunk head of the bolt being flush with the outside of member 4. The member 6 is provided with a recess [4 at its lower longitudinal edge adjacent the member 4. The recess l4 extends substantially throughout the length of the body but terminates a short distance from the rear end thereof to provide a shoulder IS. A driving member i8 is received in the recess 14 and extends therefrom with its exposed lower longitudinal edge being provided with serrations 20 as best shown in Figure 1. The end of the driving member I8 bears against the shoulder 16. By drawing the members 4 and 6 tightly together by means of the bolts 8, the driving member [8 is clamped securely in place with rearward movement thereof being prevented by the shoulder l6. Protruding plates 22 and 24 are welded to the outside of plates 4 and 6, respectively. The plates '22 and 24 each have a semi-circular bearing surface 26 merging'with an inclined rearwardly extending portion 28 which forms an angle of less than with the longitudinal axis of the body 2. The plates 4 and 6 have a cutout portion 30 at their upper edge which coincides with the sloping portions 28. The fork 32 of a spindle 34 passes over the body member 2 and is pivotally secured thereto by means of a pin 36 which passes through aligned openings in the fork 32 and clamping members 4 and 6. The free end 38 of the spindle 34 is shaped so as to be received in an air gun 40.

As shown in Figure 4, the armature body 42 which is made up of a great number of relatively thin circular metal discs is provided with circumferentially spaced openings 44. Each of the openings 44 has a substantially square crosssectional portion with the upper part thereof merging into a pair of wedge surfaces 46 which extend to within a short distance of the outside of the armature body 42. A narrow slot 48 extends from the outer portion of the wedge surface 46 to the outside of the body. Each opening 44 has windings 50 therein surrounded by insulation 52. A wedge 54 bearing against the wedge surfaces 46 hold the windings 50 and insulation 52 in place. The wedge 54 is ordinarily made of wood, fibre, Bakelite, Micarta, or like material.

The method of driving out the wedge is as follows:

The air gun 4B is placed on the free end 33 of the spindle 34 and the serrated edge 20 of the tool is placed on a wedge 54. The spindle and air gun are positioned substantially as shown in dotted lines in Figure 1 and air is momentarily applied to the air gun 40 to force the serrated edge 20 of the tool into the wedge 54 a slight distance in order to prevent slipping of the tool on the wedge as it is driven out. The spindle 34 and air gun 40 are then lowered rearwardly until the fork 32 rests on the surfaces 28. Pressure is then applied to the tool tending to move it to the right as shown in Figure 1 and at the same time air is admitted to the air gun 40.

The staccato like blows of the gun 4U create been shown and described it will be apparentthat other adaptations and modifications may be made without departing from the scopeiai the following claims:

I claim:

1. A wedge driving tool comprising an elongated body member, a driving-member fast'ened to one longitudinal edge of the body member and extending therefrom, serrations on the exposed longitudinal edge. of the driving member, a spindle pivotally mounted on'said body member at'a point 'substa'ntiallymidway"of the length thereof, an air 'gun, a p'ortiononthe end "of said spindle received'in said air'gun, said spindle being movable from a position substantially perpendicular to the longitudinal axisof the'body member 'to a rearwardly "extending 'jposition making an angle of less than 45 with the longitudinal axis of the bodymeniber; andst'op means on said body member for preventing'm'ove'm'ent of said spindle beyond said'jpositions.

2. A wedge driving"tool comprising a pair of elongated clamping rn'embe'rsfbne of i said members having a r'ecessform'ed'in the longitudinal surface adjacent the other member,la"driving member in said recess,"said"driving'memberextending from-said recessandhaving serrations f on its "exposed longitudinal edge, means for clampingthe'pair of'membejrs' together to look i the driving memberin"p1ace,'"a; spindle 'pivotally mounted on said driving "members" 2.1116," point substantially midway ofthe 'le'ngth thereof, an air gun, a"porti'on"on the "end of said spindle received in said air gunfsa'id spindle'b'eing'movable from a" position' substantially perpendicular to the longitudinal axisofthie clampingmembers to: a rearwardly extending position makingfan angleof less than 45With' thfl'on'gitudinal'axis of the clamping members, and stop means on said body member for preventing movement of said spindle beyond said positions.

3. A wedge driving tool comprising a pair of elongated clamping members, one of said members having a recess formed in the longitudinal surface adjacent the other member, said recess having a shoulder at one'end thereof, a driving member in said recess bearing against said shoulder, said driving member extending from said recess and having serrations on its exposed Jongitudinal edge, means for clamping the pair of'olamping members together to lock the driving member in place, a spindle pivotally mounted on said'driving members at a point substantialrlyl midway ofthe length thereof, an air gun,

av portion on the end of said spindle received in said air gun, said spindle being movable from a position substantially perpendicular to the longitudinal axisof the clamping members to arearwardly extending position making an 'angle of less than'-45 with the'longitudinal axis of the clamping members'andstop means on said body member for preventing movement of said spindle beyond'said positions.

WILLIAM Ill-EVANS.

REFERENCES "CITED The following references are of: record in the file of this patent:

UNITED STATES "PATENTS 

